CHAPTER 16 (PHYSICS)
When your foot stands on a tile floor, thermal energy always flow
From either your foot or the tile depending on the temperature of the tile
A good absorber of radiation is a
Good emitter of radiation
What type of gas absorbs and re-emits infrared radiation?
Greenhouse gases
The reason the Suns radient energy is of shorter wavelengths than the Earths is because the Sun
Has a higher temperature than the Earth
The relation f-t tells us that high temperature sources emit electromagnetic waves of
High frequency
In a mixture of hydrogen gas, oxygen gas and nitrogen gas, the molecules with the greatest average speed are those of
Hydrogen
When a volume of air is compressed, its temperature
Increases
Your feet feel warmer on a rug than on a tile floor because a rug
Is a better insulator than tile
Which of the following would best describe the conductive properties of wood?
It is a good insulator
What happens to the conductive properties of wood when it gets very hot?
It will continue to remain a good insulator
Hydrogen and oxygen molecules in a gas sample have the same temperature. This means the hydrogen molecules, on the average, have the same
Kinetic energy, but more speed
If a poor absorber of radiation were a good emitter, its temperature would be
Less than its surroundings
Metals are both good heat conductors and good electrical conductors because of the
Looseness of outer electrons in metal atoms
One of the main reasons one can walk barefoot on red hot coals of wood without burning the feet has to do with
Low thermal conductivity of the coals
Ceiling fans can make you feel cooler in a warm room. Do ceiling fans reduce room temperature?
NO
A good reflector of radiation is a
Poor absorber of radiation
At the same temperature which move with the greater speed in the air?
Very light molecules
How would you walk on red hot coals without getting your feet burned?
Walk fast
Which will undergo the greater rate of cooling-a red hot poker in a warm oven or a red hot poker in a cold room (or do the cool at the same rate?)
A red hot poker in a cold room
If you are able to grab a hot pan and pull it out by the handle without burning yourself, what kind of handle must the pan have, and why?
A wooden handle, because it is a better insulator
A liter of hot water will cool to room temperature faster in a
Black pot
Cold water will warm to room temperature faster in a
Black pot
Which body glows with electromagnetic waves?
Both the sun and Earth
If air were a better conductor than it is, at nighttime the Earth would be
Considerably colder
Newtons law of cooling applies to objects that undergo
Cooling or warming
When air rapidly expands, its temperature normally
Decreases
Heat travels from the sun to the Earth by the process of
Radiation
The planet Earth loses heat mainly by
Radiation
Substances absorb heat energy by the process of
Radiation, convection and conduction
Suppose you are served coffee at a restaurant before you are ready to drink it. In order for it to be the hottest when you are ready for it, you should add cream
Right away
Relatively speaking, do high frequency waves have long wavelengths or short wavelengths?
Short wavelengths
It is commonly thought that a can of beverage will cool faster in the coldest part of a refrigerator. Knowledge of Newtons law of cooling
Supports this common knowledge
How would decreasing the percentage of greenhouse gases affect the amount of infrared radiation reflected by the atmosphere back toward Earth?
The amount of infrared radiation would decrease
How would increasing the density of air in the atmosphere affect the amount of infrared radiation returned by the atmosphere back toward Earth?
The amount of infrared radiation would increase
Both black and white road surfaces absorb sunlight. At the end of a sunny day the warmer road surface will be
The black surface
Why is one able to walk on red hot coals without getting ones foot burned?
The coals are not good conductors of heat
A water filled paper cup held in a flame will not catch fire. This is because
The paper cup cannot become appreciably hotter than the water it contains
The higher temperature of an object
The shorter the wave lengths it radiates
